Pub Date : 2024-03-22DOI: 10.1016/j.aam.2024.102691
Neil J.Y. Fan , Peter L. Guo , Nicolas Y. Liu
Let be the Schubert polynomial for a permutation w of . For any given composition μ, we say that is the complement of with respect to μ. When each part of μ is equal to , Huh, Matherne, Mészáros and St. Dizier proved that the normalization of is a Lorentzian polynomial. They further conjectured that the normalization of is Lorentzian. It can be shown that if there exists a composition μ such that is a Schubert polynomial, then the normalization of will be Lorentzian. This motivates us to investigate the problem of when is a Schubert polynomial. We show that if is a Schubert polynomial, then μ must be a partition. We also consider the case when μ is the staircase partition , and obtain that
{"title":"Complements of Schubert polynomials","authors":"Neil J.Y. Fan , Peter L. Guo , Nicolas Y. Liu","doi":"10.1016/j.aam.2024.102691","DOIUrl":"https://doi.org/10.1016/j.aam.2024.102691","url":null,"abstract":"<div><p>Let <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>w</mi></mrow></msub><mo>(</mo><mi>x</mi><mo>)</mo></math></span> be the Schubert polynomial for a permutation <em>w</em> of <span><math><mo>{</mo><mn>1</mn><mo>,</mo><mn>2</mn><mo>,</mo><mo>…</mo><mo>,</mo><mi>n</mi><mo>}</mo></math></span>. For any given composition <em>μ</em>, we say that <span><math><msup><mrow><mi>x</mi></mrow><mrow><mi>μ</mi></mrow></msup><msub><mrow><mi>S</mi></mrow><mrow><mi>w</mi></mrow></msub><mo>(</mo><msup><mrow><mi>x</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>)</mo></math></span> is the complement of <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>w</mi></mrow></msub><mo>(</mo><mi>x</mi><mo>)</mo></math></span> with respect to <em>μ</em>. When each part of <em>μ</em> is equal to <span><math><mi>n</mi><mo>−</mo><mn>1</mn></math></span>, Huh, Matherne, Mészáros and St. Dizier proved that the normalization of <span><math><msup><mrow><mi>x</mi></mrow><mrow><mi>μ</mi></mrow></msup><msub><mrow><mi>S</mi></mrow><mrow><mi>w</mi></mrow></msub><mo>(</mo><msup><mrow><mi>x</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>)</mo></math></span> is a Lorentzian polynomial. They further conjectured that the normalization of <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>w</mi></mrow></msub><mo>(</mo><mi>x</mi><mo>)</mo></math></span> is Lorentzian. It can be shown that if there exists a composition <em>μ</em> such that <span><math><msup><mrow><mi>x</mi></mrow><mrow><mi>μ</mi></mrow></msup><msub><mrow><mi>S</mi></mrow><mrow><mi>w</mi></mrow></msub><mo>(</mo><msup><mrow><mi>x</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>)</mo></math></span> is a Schubert polynomial, then the normalization of <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>w</mi></mrow></msub><mo>(</mo><mi>x</mi><mo>)</mo></math></span> will be Lorentzian. This motivates us to investigate the problem of when <span><math><msup><mrow><mi>x</mi></mrow><mrow><mi>μ</mi></mrow></msup><msub><mrow><mi>S</mi></mrow><mrow><mi>w</mi></mrow></msub><mo>(</mo><msup><mrow><mi>x</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>)</mo></math></span> is a Schubert polynomial. We show that if <span><math><msup><mrow><mi>x</mi></mrow><mrow><mi>μ</mi></mrow></msup><msub><mrow><mi>S</mi></mrow><mrow><mi>w</mi></mrow></msub><mo>(</mo><msup><mrow><mi>x</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>)</mo></math></span> is a Schubert polynomial, then <em>μ</em> must be a partition. We also consider the case when <em>μ</em> is the staircase partition <span><math><msub><mrow><mi>δ</mi></mrow><mrow><mi>n</mi></mrow></msub><mo>=</mo><mo>(</mo><mi>n</mi><mo>−</mo><mn>1</mn><mo>,</mo><mo>…</mo><mo>,</mo><mn>1</mn><mo>,</mo><mn>0</mn><mo>)</mo></math></span>, and obtain that <span><math><msup><mrow><mi>x</mi></mrow><mrow><msub><mrow><mi>δ</mi></mrow><mrow><mi>n</mi></mrow></msub></mrow></msup><msub><mrow><mi>S</mi></mrow><mrow><mi>w</mi></mrow></msub><mo>(</mo><msup><mrow><mi>x</mi></mrow><","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140188239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-15DOI: 10.1016/j.aam.2024.102689
Markus Kuba , Alois Panholzer
We consider the following card guessing game with no feedback. An ordered deck of n cards labeled 1 up to n is riffle-shuffled exactly one time. Then, the goal of the game is to maximize the number of correct guesses of the cards. One after another a single card is drawn from the top, the guesser makes a guess without seeing the card and gets no response if the guess was correct or not. Building upon and improving earlier results, we provide a limit law for the number of correct guesses and also show convergence of the integer moments.
我们考虑下面这个没有反馈的猜牌游戏。一副有序的扑克牌由 n 张标有 1 至 n 的扑克牌组成,正好洗一次。然后,游戏的目标是最大限度地提高猜中牌的正确率。一张接一张的牌从最上面抽出,猜牌者在没有看到牌的情况下进行猜测,猜对与否不会得到任何回应。在先前研究成果的基础上,我们提出了正确猜测次数的极限规律,并证明了整数时刻的收敛性。
{"title":"On card guessing games: Limit law for no feedback one-time riffle shuffle","authors":"Markus Kuba , Alois Panholzer","doi":"10.1016/j.aam.2024.102689","DOIUrl":"https://doi.org/10.1016/j.aam.2024.102689","url":null,"abstract":"<div><p>We consider the following card guessing game with no feedback. An ordered deck of <em>n</em> cards labeled 1 up to <em>n</em> is riffle-shuffled exactly one time. Then, the goal of the game is to maximize the number of correct guesses of the cards. One after another a single card is drawn from the top, the guesser makes a guess without seeing the card and gets no response if the guess was correct or not. Building upon and improving earlier results, we provide a limit law for the number of correct guesses and also show convergence of the integer moments.</p></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140134017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-15DOI: 10.1016/j.aam.2024.102690
Houshan Fu , Chunming Tang , Suijie Wang
We first show that an adjoint of a loopless matroid is connected if and only if the original matroid is connected. By proving that the opposite lattice of a modular matroid is isomorphic to its extension lattice, we obtain that a modular matroid has only one adjoint (up to isomorphism) which can be given by its opposite lattice. This makes projective geometries become a key ingredient in characterizing the adjoint sequence of a connected matroid M. We classify such adjoint sequences into three types: finite, cyclic and convergent. For the first two types, the adjoint sequences eventually stabilize at finite projective geometries except for free matroids. For the last type, the infinite non-repeating adjoint sequences are convergent to infinite projective geometries.
我们首先证明,当且仅当原始矩阵是连通的时候,无环矩阵的邻接才是连通的。通过证明模状 matroid 的对立网格与它的延伸网格同构,我们得到模状 matroid 只有一个邻接点(直到同构),这个邻接点可以由它的对立网格给出。这使得投影几何成为表征连通矩阵 M 的邻接序列 ad0M、adM、ad2M......的关键要素。我们将这种邻接序列分为三种类型:有限邻接序列、循环邻接序列和收敛邻接序列。对于前两种类型,除了自由矩阵外,邻接序列最终都会稳定在有限投影几何图形上。对于最后一种类型,无限非重复邻接序列收敛于无限投影几何图形。
{"title":"Adjoints of matroids","authors":"Houshan Fu , Chunming Tang , Suijie Wang","doi":"10.1016/j.aam.2024.102690","DOIUrl":"https://doi.org/10.1016/j.aam.2024.102690","url":null,"abstract":"<div><p>We first show that an adjoint of a loopless matroid is connected if and only if the original matroid is connected. By proving that the opposite lattice of a modular matroid is isomorphic to its extension lattice, we obtain that a modular matroid has only one adjoint (up to isomorphism) which can be given by its opposite lattice. This makes projective geometries become a key ingredient in characterizing the adjoint sequence <span><math><mi>a</mi><msup><mrow><mi>d</mi></mrow><mrow><mn>0</mn></mrow></msup><mi>M</mi><mo>,</mo><mi>a</mi><mi>d</mi><mi>M</mi><mo>,</mo><mi>a</mi><msup><mrow><mi>d</mi></mrow><mrow><mn>2</mn></mrow></msup><mi>M</mi><mo>,</mo><mo>…</mo></math></span> of a connected matroid <em>M</em>. We classify such adjoint sequences into three types: finite, cyclic and convergent. For the first two types, the adjoint sequences eventually stabilize at finite projective geometries except for free matroids. For the last type, the infinite non-repeating adjoint sequences are convergent to infinite projective geometries.</p></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140134175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-12DOI: 10.1016/j.aam.2024.102676
Pedro Ribeiro, Semyon Yakubovich
Recently, Dixit et al. [24] established a very elegant generalization of Hardy's theorem concerning the infinitude of zeros that the Riemann zeta function possesses at its critical line.
By introducing a general transformation formula for the theta function involving the Bessel and modified Bessel functions of the first kind, we extend their result to a class of Dirichlet series satisfying Hecke's functional equation. In the process, we also find new generalizations of classical identities in Analytic number theory.
{"title":"Certain extensions of results of Siegel, Wilton and Hardy","authors":"Pedro Ribeiro, Semyon Yakubovich","doi":"10.1016/j.aam.2024.102676","DOIUrl":"https://doi.org/10.1016/j.aam.2024.102676","url":null,"abstract":"<div><p>Recently, Dixit et al. <span>[24]</span> established a very elegant generalization of Hardy's theorem concerning the infinitude of zeros that the Riemann zeta function possesses at its critical line.</p><p>By introducing a general transformation formula for the theta function involving the Bessel and modified Bessel functions of the first kind, we extend their result to a class of Dirichlet series satisfying Hecke's functional equation. In the process, we also find new generalizations of classical identities in Analytic number theory.</p></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140103337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-12DOI: 10.1016/j.aam.2024.102688
Dariusz Bugajewski , Dawid Bugajewski , Xiao-Xiong Gan , Piotr Maćkowiak
The famous J.C.P. Miller formula provides a recurrence algorithm for the composition , where is the formal binomial series and f is a formal power series, however it requires that f has to be a nonunit.
In this paper we provide the general J.C.P. Miller formula which eliminates the requirement of nonunitness of f and, instead, we establish a necessary and sufficient condition for the existence of the composition . We also provide the general J.C.P. Miller recurrence algorithm for computing the coefficients of that composition, if is well defined, obviously. Our generalizations cover both the case in which f is a one–variable formal power series and the case in which f is a multivariable formal power series.
In the central part of this article we state, using some combinatorial techniques, the explicit form of the general J.C.P. Miller formula for one-variable case.
As applications of these results we provide an explicit formula for the inverses of polynomials and formal power series for which the inverses exist, obviously. We also use our results to investigation of approximate solution to a differential equation which cannot be solved in an explicit way.
著名的 J.C.P. Miller 公式为 Ba∘f 的组成提供了一种递推算法,其中 Ba 是形式二项式级数,f 是形式幂级数,但它要求 f 必须是非整数。在本文中,我们提供了一般的 J.C.P. Miller 公式,它消除了 f 的非整数性要求,相反,我们建立了组成 Ba∘f 存在的必要条件和充分条件。显然,如果 Ba∘f 定义良好,我们还提供了计算该组成系数的一般 J.C.P. 米勒递推算法。在本文的中心部分,我们利用一些组合技术,说明了一变量情况下一般 J.C.P. 米勒公式的显式形式。作为这些结果的应用,我们提供了多项式和形式幂级数倒数的显式公式,显然,这些倒数是存在的。我们还利用这些结果研究了无法用显式方法求解的微分方程的近似解。
{"title":"On the recursive and explicit form of the general J.C.P. Miller formula with applications","authors":"Dariusz Bugajewski , Dawid Bugajewski , Xiao-Xiong Gan , Piotr Maćkowiak","doi":"10.1016/j.aam.2024.102688","DOIUrl":"https://doi.org/10.1016/j.aam.2024.102688","url":null,"abstract":"<div><p>The famous J.C.P. Miller formula provides a recurrence algorithm for the composition <span><math><msub><mrow><mi>B</mi></mrow><mrow><mi>a</mi></mrow></msub><mo>∘</mo><mi>f</mi></math></span>, where <span><math><msub><mrow><mi>B</mi></mrow><mrow><mi>a</mi></mrow></msub></math></span> is the formal binomial series and <em>f</em> is a formal power series, however it requires that <em>f</em> has to be a nonunit.</p><p>In this paper we provide the general J.C.P. Miller formula which eliminates the requirement of nonunitness of <em>f</em> and, instead, we establish a necessary and sufficient condition for the existence of the composition <span><math><msub><mrow><mi>B</mi></mrow><mrow><mi>a</mi></mrow></msub><mo>∘</mo><mi>f</mi></math></span>. We also provide the general J.C.P. Miller recurrence algorithm for computing the coefficients of that composition, if <span><math><msub><mrow><mi>B</mi></mrow><mrow><mi>a</mi></mrow></msub><mo>∘</mo><mi>f</mi></math></span> is well defined, obviously. Our generalizations cover both the case in which <em>f</em> is a one–variable formal power series and the case in which <em>f</em> is a multivariable formal power series.</p><p>In the central part of this article we state, using some combinatorial techniques, the explicit form of the general J.C.P. Miller formula for one-variable case.</p><p>As applications of these results we provide an explicit formula for the inverses of polynomials and formal power series for which the inverses exist, obviously. We also use our results to investigation of approximate solution to a differential equation which cannot be solved in an explicit way.</p></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140103338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We study substitutions on a countably infinite alphabet (without compactification) as Borel dynamical systems. We construct stationary and non-stationary generalized Bratteli-Vershik models for a class of such substitutions, known as left determined. In this setting of Borel dynamics, using a stationary generalized Bratteli-Vershik model, we provide a new and canonical construction of shift-invariant measures (both finite and infinite) for the associated class of subshifts.
{"title":"Substitution-dynamics and invariant measures for infinite alphabet-path space","authors":"Sergey Bezuglyi , Palle E.T. Jorgensen , Shrey Sanadhya","doi":"10.1016/j.aam.2024.102687","DOIUrl":"https://doi.org/10.1016/j.aam.2024.102687","url":null,"abstract":"<div><p>We study substitutions on a countably infinite alphabet (without compactification) as Borel dynamical systems. We construct stationary and non-stationary generalized Bratteli-Vershik models for a class of such substitutions, known as <em>left determined</em>. In this setting of Borel dynamics, using a stationary generalized Bratteli-Vershik model, we provide a new and canonical construction of shift-invariant measures (both finite and infinite) for the associated class of subshifts.</p></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140113410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-04DOI: 10.1016/j.aam.2024.102675
Michael Ren
Building off recent work of Garg and Peng, we continue the investigation into classical and consecutive pattern avoidance in rooted forests, resolving some of their conjectures and questions and proving generalizations whenever possible. Through extensions of the forest Simion-Schmidt bijection introduced by Anders and Archer, we demonstrate a new family of forest-Wilf equivalences, completing the classification of forest-Wilf equivalence classes for sets consisting of a pattern of length 3 and a pattern of length at most 5. We also find a new family of nontrivial c-forest-Wilf equivalences between single patterns using the forest analogue of the Goulden-Jackson cluster method, showing that a -fraction of patterns of length n satisfy a nontrivial c-forest-Wilf equivalence and that there are c-forest-Wilf equivalence classes of patterns of length n of exponential size. Additionally, we consider a forest analogue of super-strong-c-Wilf equivalence, introduced for permutations by Dwyer and Elizalde, showing that super-strong-c-forest-Wilf equivalences are trivial by enumerating linear extensions of forest cluster posets.
{"title":"Wilf equivalences for patterns in rooted labeled forests","authors":"Michael Ren","doi":"10.1016/j.aam.2024.102675","DOIUrl":"https://doi.org/10.1016/j.aam.2024.102675","url":null,"abstract":"<div><p>Building off recent work of Garg and Peng, we continue the investigation into classical and consecutive pattern avoidance in rooted forests, resolving some of their conjectures and questions and proving generalizations whenever possible. Through extensions of the forest Simion-Schmidt bijection introduced by Anders and Archer, we demonstrate a new family of forest-Wilf equivalences, completing the classification of forest-Wilf equivalence classes for sets consisting of a pattern of length 3 and a pattern of length at most 5. We also find a new family of nontrivial c-forest-Wilf equivalences between single patterns using the forest analogue of the Goulden-Jackson cluster method, showing that a <span><math><msup><mrow><mo>(</mo><mn>1</mn><mo>−</mo><mi>o</mi><mo>(</mo><mn>1</mn><mo>)</mo><mo>)</mo></mrow><mrow><mi>n</mi></mrow></msup></math></span>-fraction of patterns of length <em>n</em> satisfy a nontrivial c-forest-Wilf equivalence and that there are c-forest-Wilf equivalence classes of patterns of length <em>n</em> of exponential size. Additionally, we consider a forest analogue of super-strong-c-Wilf equivalence, introduced for permutations by Dwyer and Elizalde, showing that super-strong-c-forest-Wilf equivalences are trivial by enumerating linear extensions of forest cluster posets.</p></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140030432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-14DOI: 10.1016/j.aam.2024.102678
Robert S. Maier
Ordering identities in the Weyl–Heisenberg algebra generated by single-mode boson operators are investigated. A boson string composed of creation and annihilation operators can be expanded as a linear combination of other such strings, the simplest example being a normal ordering. The case when each string contains only one annihilation operator is already combinatorially nontrivial. Two kinds of expansion are derived: (i) that of a power of a string Ω in lower powers of another string , and (ii) that of a power of Ω in twisted versions of the same power of . The expansion coefficients are shown to be, respectively, generalized Stirling numbers of Hsu and Shiue, and certain generalized Eulerian numbers. Many examples are given. These combinatorial numbers are binomial transforms of each other, and their theory is developed, emphasizing schemes for computing them: summation formulas, Graham–Knuth–Patashnik (GKP) triangular recurrences, terminating hypergeometric series, and closed-form expressions. The results on the first type of expansion subsume a number of previous results on the normal ordering of boson strings.
{"title":"Boson operator ordering identities from generalized Stirling and Eulerian numbers","authors":"Robert S. Maier","doi":"10.1016/j.aam.2024.102678","DOIUrl":"https://doi.org/10.1016/j.aam.2024.102678","url":null,"abstract":"<div><p>Ordering identities in the Weyl–Heisenberg algebra generated by single-mode boson operators are investigated. A boson string composed of creation and annihilation operators can be expanded as a linear combination of other such strings, the simplest example being a normal ordering. The case when each string contains only one annihilation operator is already combinatorially nontrivial. Two kinds of expansion are derived: (i) that of a power of a string Ω in lower powers of another string <span><math><msup><mrow><mi>Ω</mi></mrow><mrow><mo>′</mo></mrow></msup></math></span>, and (ii) that of a power of Ω in twisted versions of the same power of <span><math><msup><mrow><mi>Ω</mi></mrow><mrow><mo>′</mo></mrow></msup></math></span>. The expansion coefficients are shown to be, respectively, generalized Stirling numbers of Hsu and Shiue, and certain generalized Eulerian numbers. Many examples are given. These combinatorial numbers are binomial transforms of each other, and their theory is developed, emphasizing schemes for computing them: summation formulas, Graham–Knuth–Patashnik (GKP) triangular recurrences, terminating hypergeometric series, and closed-form expressions. The results on the first type of expansion subsume a number of previous results on the normal ordering of boson strings.</p></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139732739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-12DOI: 10.1016/j.aam.2024.102671
D. Hanson , A.V. Shepler
Much of the captivating numerology surrounding finite reflection groups stems from Solomon's celebrated 1963 theorem describing invariant differential forms. Invariant differential derivations also exhibit fascinating numerology over the complex numbers linked to rational Catalan combinatorics. We explore the analogous theory over arbitrary fields, in particular, when the characteristic of the underlying field divides the order of the acting reflection group and the conclusion of Solomon's Theorem may fail. Using results of Broer and Chuai, we give a Saito criterion (Jacobian criterion) for finding a basis of differential derivations invariant under a finite group that distinguishes certain cases over fields of characteristic 2. We show that the reflecting hyperplanes lie in a single orbit and demonstrate a duality of exponents and coexponents when the transvection root spaces of a reflection group are maximal. A set of basic derivations are used to construct a basis of invariant differential derivations with a twisted wedging in this case. We obtain explicit bases for the special linear groups and general linear groups , and all groups in between.
{"title":"Invariant differential derivations for reflection groups in positive characteristic","authors":"D. Hanson , A.V. Shepler","doi":"10.1016/j.aam.2024.102671","DOIUrl":"https://doi.org/10.1016/j.aam.2024.102671","url":null,"abstract":"<div><p>Much of the captivating numerology surrounding finite reflection groups stems from Solomon's celebrated 1963 theorem describing invariant differential forms. Invariant differential derivations also exhibit fascinating numerology over the complex numbers linked to rational Catalan combinatorics. We explore the analogous theory over arbitrary fields, in particular, when the characteristic of the underlying field divides the order of the acting reflection group and the conclusion of Solomon's Theorem may fail. Using results of Broer and Chuai, we give a Saito criterion (Jacobian criterion) for finding a basis of differential derivations invariant under a finite group that distinguishes certain cases over fields of characteristic 2. We show that the reflecting hyperplanes lie in a single orbit and demonstrate a duality of exponents and coexponents when the transvection root spaces of a reflection group are maximal. A set of basic derivations are used to construct a basis of invariant differential derivations with a twisted wedging in this case. We obtain explicit bases for the special linear groups <span><math><mtext>SL</mtext><mo>(</mo><mi>n</mi><mo>,</mo><mi>q</mi><mo>)</mo></math></span> and general linear groups <span><math><mtext>GL</mtext><mo>(</mo><mi>n</mi><mo>,</mo><mi>q</mi><mo>)</mo></math></span>, and all groups in between.</p></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139718307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-09DOI: 10.1016/j.aam.2024.102670
Saugata Basu , Ali Mohammad-Nezhad
It is well-known that the central path of semi-definite optimization, unlike linear optimization, has no analytic extension to in the absence of the strict complementarity condition. In this paper, we consider a reparametrization , with ρ being a positive integer, that recovers the analyticity of the central path at . We investigate the complexity of computing ρ using algorithmic real algebraic geometry and the theory of complex algebraic curves. We prove that the optimal ρ is bounded by , where n is the matrix size and m is the number of affine constraints. Our approach leads to a symbolic algorithm, based on the Newton-Puiseux algorithm, which computes a feasible ρ using arithmetic operations.
{"title":"On the complexity of analyticity in semi-definite optimization","authors":"Saugata Basu , Ali Mohammad-Nezhad","doi":"10.1016/j.aam.2024.102670","DOIUrl":"https://doi.org/10.1016/j.aam.2024.102670","url":null,"abstract":"<div><p>It is well-known that the central path of semi-definite optimization, unlike linear optimization, has no analytic extension to <span><math><mi>μ</mi><mo>=</mo><mn>0</mn></math></span> in the absence of the strict complementarity condition. In this paper, we consider a reparametrization <span><math><mi>μ</mi><mo>↦</mo><msup><mrow><mi>μ</mi></mrow><mrow><mi>ρ</mi></mrow></msup></math></span>, with <em>ρ</em> being a positive integer, that recovers the analyticity of the central path at <span><math><mi>μ</mi><mo>=</mo><mn>0</mn></math></span>. We investigate the complexity of computing <em>ρ</em> using algorithmic real algebraic geometry and the theory of complex algebraic curves. We prove that the optimal <em>ρ</em> is bounded by <span><math><msup><mrow><mn>2</mn></mrow><mrow><mi>O</mi><mo>(</mo><msup><mrow><mi>m</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>+</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mi>m</mi><mo>+</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>4</mn></mrow></msup><mo>)</mo></mrow></msup></math></span>, where <em>n</em> is the matrix size and <em>m</em> is the number of affine constraints. Our approach leads to a symbolic algorithm, based on the Newton-Puiseux algorithm, which computes a feasible <em>ρ</em> using <span><math><msup><mrow><mn>2</mn></mrow><mrow><mi>O</mi><mo>(</mo><mi>m</mi><mo>+</mo><msup><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>)</mo></mrow></msup></math></span> arithmetic operations.</p></div>","PeriodicalId":50877,"journal":{"name":"Advances in Applied Mathematics","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139714968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}